The invention relates to a milling head having a basic body and at least one cutting insert which is clamped in the basic body by means of a clamping element and whose position can be adjusted, wherein the cutting insert extends in a recess of the basic body and adjusting means which are in engagement are provided for the purpose of adjusting the cutting insert. Furthermore, the invention relates to a milling head having a basic body and cutting inserts which can be adjusted in the basic body in each case in recesses and are clamped by means of a clamping element which is disposed in a recess, wherein the cutting insert is positioned in a positive-fitting manner in a receiving part and is fixed in its position by means of the clamping element.
Milling heads of this kind are used in particular for milling at high rotational speeds and are subjected to correspondingly high stresses. In particular, it is important that the cutting inserts maintain their position, in order on the one hand to maintain the processing accuracy and on the other hand to obviate any risk of accidents occurring.
In the case of a milling head which is disclosed in DE 40 03 862 C2, the cutting inserts are disposed in recesses of the basic body and can be adjusted in an axial and radial direction. It is possible to clamp the cutting inserts with the aid of round wedges. The basic body comprises a cooling arrangement [not illustrated]. The axis of the round wedges is disposed in each case skewed with respect to the axis of the cutting inserts, wherein the round wedges are themselves disposed in turn in recesses of the basic body. The arrangement is such that the recesses of the cutting insert and the basic body are connected to each other and the cutting inserts are clamped by virtue of the round wedges against a wall region of the basic body and are held in this manner in the recess. The round wedge is provided in each case with a planar clamping surface in order to achieve an effective clamping contact.
In the case of a different milling head in accordance with DE 35 30 745 A1, the basic body comprises a plurality of grooves which are disposed substantially in a radial direction, issue into an outer peripheral region and into an end face region and in which in each case a cutting insert is disposed which can be adjusted in an axial and radial direction by means of adjusting devices. Since the grooves issue into both the end face region and into the outer peripheral region of the basic body, it is possible to use cutting inserts having various dimensions. In order to fix the cutting insert to the basic body, a clamping device is provided in the form of a clamping screw.
A common aspect of these and other milling heads is that the cutting inserts can be adjusted radially and axially. This is adequate for a number of applications. However, it is often required to adjust the cutting insert(s) to a greater extent, i.e. three-dimensional adjustability.
Another common aspect of these and other milling heads is the presence of an open recess, in which the cutting inserts are located and clamped by means of clamping elements. This peripheral recess or milled-out section serves to produce a smaller core diameter of the basic body as a variable which determines stability. Furthermore, as mentioned it is not possible to exclude the slight probability that the cutting inserts and clamping elements located in the open recess can become detached at the high rotational speeds employed and thus cause accidents.
U.S. Pat. No. 2,846,757 A describes a milling head having a basic body and at least one cutting insert which can be clamped in the basic body by means of a clamping element and its position can be adjusted. The cutting insert extends in a recess of the basic body and adjusting means which are in engagement are provided for the purpose of adjusting the cutting insert, wherein the cutting insert comprises a pivot mounting for adjustment purposes and on both sides of the pivot two adjusting screws are provided in the cutting insert for the purpose of fixing the pivot movement of the cutting insert. However, this pivot mounting is secured in the basic body and is thus fixed. It permits a tilting movement but not a longitudinal adjustment of the cutting insert.
Furthermore, DE 44 30 197 A discloses a tool for fine-machining the inner surfaces of bores. The basic body of this fine-machining tool is provided with a slot, of which the width can be varied by means of an adjusting device for the purpose of adjusting the diameter of the cutter.
In the case of a milling head in accordance with U.S. Pat. No. 4,964,763 A having a basic body and a cutting insert which can be adjusted in the basic body in a recess and is clamped by means of a clamping element which is disposed in a recess, the cutting insert is positioned in a positive-fitting manner in a receiving part and is fixed in its position by means of the clamping element. The clamping element is provided in the form of a wedge pin and a threaded pin. This can impair the operational reliability owing to possible torsional stresses and the tendancy of the cutting plate to vibrate.
DE 296 06 165 U describes a bevel milling apparatus whose cutting tools can be pivoted by being mounted in a centred manner on a holding body which can be rotated about an axis.
It is the object of the invention to provide a milling head which renders it possible for the cutting inserts to be used at high rotational speeds and to be adjusted in an extremely precise manner.
This object is achieved in accordance with the invention in the case of a milling head having the features of claim 1. Advantageous embodiments of the milling head in accordance with the invention are the subject matter of the subordinate claims.